2024 Aluminum alloy is widely used in aircraft structures, truck wheels, rivets, screw machine products, scientific instruments, vetniary and orthopedic braces and equipment. Normal composition of the alloy is Cu 4.0%, Mn 0.7%, Mg 0.8%, Si 0.5% and balance Al .The heat treatment process used for this alloy is solution treatment at 495 oC followed by quenching in flowing water and then natural aging at room temp for four days. Main phase that precipitates out upon natural aging after solution treatment is CuMgAl2 and Mg2Si found by X-Ray diffraction. If the quenching temp due to any reason goes beyond 500 oC the over burning of the phase Mg2Si occurs. Over burning is grouped into three categories a) Slightly over burning, b)Normal over burning, c)Serious over burning.

In the present work samples of 2024 alloy were heat treated (T-6) at different temperatures and then effect of over burning on microstructure and mechanical properties were studied.